Various airbag restraint systems are known in which a door covers the airbag restraint components prior to deployment of an airbag into the vehicle passenger compartment.
U.S. Pat. No. 3,622,176 discloses a cover with a perforated outer skin. The problem with such an arrangement is that weakened sections of the perforated outer skin tend to collapse inwardly to be visible and thus do not fully conceal the underlying airbag restraint system. Furthermore, such systems depend upon the force of the inflating airbag to tear the cover to form a deployment opening therein. Such tearing can at times hinder deployment in an undesirable manner.
U.S. Pat. No. 3,708,179 discloses a door assembly for an airbag restraint including two recessed metal doors that hinge open when the airbag is deployed.
U.S. Pat. No. 4,097,064 discloses a cover assembly which carries a cutter to pierce the outer skin of the cover assembly. However, the '064 arrangement requires a separate inertially responsive shield for protecting the airbag during its deployment.
U.S. Pat. No. 4,246,213 discloses a cover assembly that includes a cover having weakened sections in the outer shell or skin of a cover assembly. The '213 arrangement depends upon tearing of the outer skin at the weakened sections for airbag deployment and presents the same disadvantages as in the case of the '176 patent.
U.S. Pat. No. 4,327,937 discloses a door for an airbag restraint system formed by molding a boundary edge on an all plastic door for retention in a fixed body part.